Process of making sodium sulfate and sulfuric acid.



OSKAR ZAHN, OF BERLIN, GERMANY.

PROCESS OF MAKING SODIUM Specification of Letters Patent.

SULFATE AND SULFURIO ACID.

Patented May 11, 1909.

Application filed October 28, 1907. Serial No. 899,403.

To all whom it may. concern: Be it known that I, OSKAR ZAHN, a subiect of the Austrian Emperor, residing at Berin, Prussia, German Empire, have invented g certain new and useful Im )rovements ini Processes of Manufacturing odium Sulfate 1 and Sulfuric Acid, of which the following is a specification. I The subject of my invention is a process of manufacturing sulfate of soda and sul- 3 furic acid from bisulfate of soda.

y invention consists in converting the sodium bisulfate into sodium sulfate and hydrated sulfuric acid by the addition of water, and in then eva orating the acid and calcining the sulfate o tained.

rocess is alread well known according to W 'ch there is ad ed to the sodium bisulfate so much water that the resulting sulfate can crystallize. For this purpose, for each molecule of sodium sulfate ten molecules of water would be necessary, apart from the uantity of water requisite for producing ydrated sulfuric acid. In this process the crystals obtained are se arated rom the sulfuric acid and each su stance used separately. In order to obtain calcined sulfate by this rocess, the cr ,stallized salt would have to e deprived 0 its water of crystallization in a s ecial furnace. Only if this were done, cou d calcined sulfate be obtained.

According to my new trary, I only add such permits of hydrated sul uric acid being roduced. hus any excess of water, w ich might serve as water of crystallization, is alto ether avoided.

The advantage of my improved method is that the mixture of hydrated acid and sulfate can be process, on the conuantlty of water as Introduced direct into the furnace, without its being necessary to drive off water of crystallization. By this means fuel is essentially economized, and what is {of still more importance, there results a great saving of time and wages, owing to there being no intermediate operation required.

My new process might, for instance, be carried out as f0ll0Ws:T he bisulfate (say 5 100 kilograms) is broken into pieces and laced in an iron pan, resembling those used or sulfate furnaces, and worked up with, say, from 67 kilograms of water, and thus dissolved. The pan may be adequately heated for the purpose. In the course of the process a part of the hydrated sulfuric acld escapes. he reaction-mixture gradually assumes a pasty consistency and can then be transferred to a roaster, in which the sulfate is calcined.

As already ex lained, in my new rocess there is no bisul ate introduced into t e furnace, but onlysulfate, mixed with a small quantity of sulfuric acid. There is thus no appreciable wear and tear of the material 0 the furnace, whereby the process is rendered very economical.

The temperatures used in the carrying out of the process are as follows: in the iron pan about 150-200 degrees, in the roaster about 1000 degrees.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent is The process of manufacturing sodium sulfate and sulfuric acid, consisting in decomposing sodium bisulfate, with the aid of water, into sodium sulfate and hydrated sulfuric acid, and in heating the same to drive off this acid and to calcine the sulfate, substantially as described.

In testimony whereof I aflix my signature in presence of two witnesses.

OSKAR ZAHN.

Witnesses:

HERMANN BREY, O'r'ro STEUER. 

